I am getting this issue also with appliance v3, checked my Appliance version and noticed it was not compatible as we are running vCenter 3721164.

Tried the 3.1 appliance, same issue.

I've resolved my issue by cleaning up DNS entries that were initially created by the appliance and then restarting the appliance and unregister/re-register.

did you solved this error? is happenning the same to me.....

Thanks in advance.

4 years and no technicians from dell to help....

Hello,

What troubleshooting steps have you taken so far? What software versions do you have installed?

Like Shaunchristides had mentioned in his post, restarting and re-registering the appliance is a fix I've seen work in several instances.